


I'll Be There For You

by ohstardustgirl



Category: Rogue One: A Star Wars Story (2016)
Genre: Alternate Universe - Everyone Lives/Nobody Dies, Cassian and K-2SO friendship, Droid Autonomy, F/M, Rebelcaptain - Freeform, The Welcome Home Scene, Tumblr Prompt, cos he second chapter is post-scarif, orbiting, well some people die
Language: English
Status: Completed
Published: 2017-07-21
Updated: 2017-07-26
Packaged: 2018-12-05 05:09:07
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 3,682
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11570979
Author URL: https://archiveofourown.org/users/ohstardustgirl/pseuds/ohstardustgirl
Summary: Chapter 1: @thestarbirdfromtheashes requested the Welcome Home scene, in particular what Cassian and K-2SO had said to each other to prompt the droid promising to be by Jyn's side.Chapter 2: @rover-Kelevra then asked for a follow-up discussion between Cassian and K-2SO after they survive ScarifChapter 3: Jyn and K-2SO have a chat about loyalty and Cassian.





	1. Chapter 1

**Author's Note:**

  * For [Starbird](https://archiveofourown.org/users/Starbird/gifts), [RoverKelevra](https://archiveofourown.org/users/RoverKelevra/gifts).



He doesn’t have much time, he knows. Ahead of him he can hear the shouts coming from the Council room, a sure sign that tempers are flaring and that the meeting will soon be called to a close by Mothma’s cool pragmatism. Behind him the ragtag crew of assassins and soldiers he has assembled is milling, fuelled by nervous energy waiting to be presented like the gift that they are to the daughter of the very man who created the weapon that could destroy them all. 

Cassian knows what this mission will be. Infiltrating an Imperial base, even with months of planning and just his own skin to worry about, is one thing - trying to sneak a platoon of rebel soldiers in will come with a high body count. They’ve all assented though, fully aware of the risks.

All but one.

K-2SO is standing to one side, watching and listening to the raucous soldiers.

“Kay,” Cassian asks, looking up at his friend, “You don’t have to come, if you don’t want to.”

The droid cocks his head, and Cassian almost chuckles at how _human_ the gesture is. “I have a choice in whether or not I want to go on a suicide mission? Since when?”

“Since always, Kay. You always have a choice.” He shakes his head. “There’s a good chance we won’t come back from this one.”

“There’s a 93.574 per cent chance of your death. And a 78 per cent chance of my own destruction.”

Cassian swallows down the sudden surge of nausea that rolls high in his stomach. K-2SO’s statistics have never failed to have that effect, reality like the slap to the face he had delivered on Jedha. He nods. “I know, Kay. And if you’re coming with us, I have an important job for you.”

“More important than protecting you?”

“Yes, Kay. You don’t have to come on this mission, or put yourself at risk if you don’t want to. But if you are joining us, then I am ordering you to make this job your priority.”

“What is so important, Cassian?”

The words don’t want to come out. The droid has seen Cassian at his worst. He’s seen him broken and shaking with blood on his hands after taking lives that should have been spared. He’s listened to his ramblings as fevers and alcohol and sleep deprivation made him pour out his broken, battered heart. But this is something new, something tender that makes Cassian feel as if his skin has been flayed.

“I need you to take care of Jyn. Before anyone else, before the mission - ”

“Before the mission?” Kay practically squawks, momentarily flaring up to his full height. 

“Yes,” Cassian snaps more harshly than he intended as the soldiers quieten around them, before returning to their nervous chatter. He speaks quietly. “For me. She deserves… she deserves better, better than what she’s had. If I don’t make it, I need you to be there for her. Help her. If there’s any chance of getting her out of there, take it.”

The droid is silent for a long moment, staring down at Cassian, head once again to one side like a tooka cat being whistled at. 

“You’ve been compromised.”

“I think you’re right, Kay.” He thinks they’re the hardest words he’s ever had to say, and as he catches Jyn and Bodhi stalking towards the Guardians with rage in their steps, he knows worse is still to come. 

“You’re putting Jyn Erso’s life before the mission. _You._ ”

Cassian sighs. “Kay, don’t ask me to explain, because I don’t think I even understand it. Just… either promise me, or take it as an order. Your choice.”

The droid is silent again for several beats, golden ocular units staring him down, and Cassian would give a thousand credits to figure out how exactly his attempt at reprogramming a security droid to save his own skin had resulted in _this_.

“Your behaviour has become unpredictable.”

“I know.”

“I now assess your chance of survival as having decreased by 2.7%. I do not see this as a valid reason for me to treat Jyn Erso well.” Kay straightened again. “I will consider it as… a favour. To a friend.”

Cassian smiles, feeling like the air has been knocked from his lungs. He only has so many words to spare today, too many difficult ones, so he raps his hand against the droid’s chassis and turns to see Jyn’s gaze meet his. Her body stiffens, and her expression is angry, defensive, as if she had just been pulled from Wobani again. As he speaks, promises himself to her, places the responsibility of his absolution on her desire, she softens beautifully. 

He very much wants to see her smile more, feel the shape of it beneath his own lips.

And then, as it’s about to be just him and her and something electric in the air between them, Kay steps forward.

“Jyn, I’ll be there for you.” A beat. “Cassian said I have to.”

The droid stomps off. He can’t find it in him to care at all that Kay has just exposed him to her, not when she’s smiling at him like he’s someone who deserves to have something so beautiful given to him.

He walks towards her before he realises he’s moving, drawn into her orbit, planets spinning around each other unable to survive alone. The last few hours are the furthest apart they’ve been since they met, other than when he was imprisoned on Jedha, and he wonders if that was what drove him to escape and find her even as the ground crumbled, if that was why his heart pounded and his skin itched the whole time. He had blamed it on the imprisonment.

“I’m not used to someone sticking around when things go bad.” She says, green eyes sparkling and corners of her lips turned up, cheeks flushed. He can’t look away, and his traitorous mind drifts to thoughts of kissing her. She is incandescent, the need in her eyes that has hypnotised him since she was tempted with the possibility of finding Galen Erso makes it impossible to look away. She is _alive_ and burning with purpose. Cassian isn’t much of a believer but he hopes that the Force will see her through this so that she can always look like this, so that she can always set the Alliance alight and walk through fire for the cause. He says the only thing that seems appropriate in that moment, words he hopes to say again, and catches her eyes dropping to his lips and thinks maybe Jyn Erso might want to kiss him as much as he wants to kiss her.

_“Welcome home.”_


	2. Chapter 2

**Summary for the Chapter:**

> Cassian and K-2SO discuss the promise the droid made after Scarif.

Cassian wakes, and that very fact surprises him. 

The last time he had closed his eyes he was as good as dead, kneeling on the beach with Jyn Erso in his arms and the shockwave from the Death Star was hurtling towards them. His broken, aching body had been ready to shut down and wouldn’t have carried him much further anyway.

Except somehow it did, he thinks as he blinks in the bright lights and white walls of what appears to be a sterile med bay. He can feel the hum of space travel, smell the acidity of bacta on his skin, and the ceiling above him is lit with strips of white light. He risks a deep breath, feels it travel past a dry throat all the way to the bottom of his lungs and back again, without the pain that had marred what should have been his final moments. 

A shadow suddenly looms over him, blocking out the light from above. 

“Kay?” His voice is scratchy and raw, and his chest swells at the sight of the droid. Except it’s not quite the droid he knew, because he’s missing all of the dents and scrapes and scars that marked him as unique. A new chassis. Cassian wonders if he’s dead after all, if he’s in some afterlife where everyone he lost is suddenly restored.

“Cassian,” the droid speaks in a voice not quite the same as before, as if it wasn’t quite used to speaking outside of the small vocabulary of a standard KX security droid. It’s how Kay had sounded so many years ago when he was newly reprogrammed. “Do not move. You have been immobile for a number of days.”

Cassian swallows past the dryness in his throat. “Where are we?”

“You are on the Mon Cala cruiser which is assisting in the evacuation of Yavin. The plans were transmitted to the fleet. The Death Star was destroyed, but not before the base at Yavin was discovered. Your mission was a success, by all accounts.” The droid straightens and the room gets brighter. “Although only you and Jyn Erso returned from Scarif.”

Cassian scrunches his eyes closed against the light as his mind tries to process the overload of information. The Death Star is gone and Jyn is alive. All those good men who followed them to Scarif gave their lives, and yet of all people he was the one who survived. He feels elated and ill and furious at the same time. He doesn’t know if he deserves to be here, but by the Force he can’t help the undeniable sense of relief that rushes right down to his gut like ice water. 

“Where is Jyn?” He tries to sit up and the room sways and spins around him and he thinks he might be sick. His body trembles from the sudden movement after so much recovery and rest and he takes deep breaths through his nose until everything stops moving quite so much.

K-2SO raises a hand and points to the other side of Cassian’s bed, and his heart jumps.

Jyn is curled up on her side, on a bunk next to his within arm’s reach. Her hair is loose around her face and she is dressed in soft white clothing. The pale skin exposed to him is littered with small cuts and bruises, but otherwise she is pink and healthy and alive. Her body moves with gentle, regular breaths and he feels is own chest rise and fall in sync. 

It’s been a long time since he has been happy to be alive. 

“Is she -”

“She was only mildly injured. Your own injuries were near fatal - broken spine and ribs, ruptured spleen and internal bleeding, not to mention the concussion and torn ligaments.” The droid makes a sound that is almost a sigh. “It seems you were the one that needed looking after, not her. Although had I not agreed to the favour of prioritising protecting Jyn, I do not believe it would have occurred to me to have taken the steps which ultimately secured your survival.”

“How did we survive? How did you survive, Kay? I heard you die.” 

“I ran a number of simulations to calculate which scenario would give the best odds of Jyn escaping, since that was the favour I promised you. Uploading my programming to another KX droid yielded the highest probability of her survival. After my old body was destroyed, this one was able to secure a shuttle and provide means of escape.”

“Kay, I… thank you. You never fail to make me proud, my friend.” Cassian rapped on the droid’s chest, and thought back to the moment in the tower when he thought he would never get to repeat that affectionate gesture again. “I know what I asked of you might not have made sense.”

“Jyn Erso has vehemently refused to leave your side since I found you on the beach. There is no reason for her to still be in the med bay with you.” Kay looks down at the ground as if shy. “I find her loyalty to be admirable. Her continued existence seems to make you happy, and this increases the odds of your survival considerably. Therefore I will… continue to offer her my protection.”

Cassian doesn’t have the words. His eyes burn and his throat locks up. K-2SO has been his partner and confidante for the better part of a decade, fiercely protective of Cassian only and the droid’s loyalty to anyone else without being ordered is something new. He feels not only grateful but unworthy of his friendship. He blinks away the tears that threaten.

“Things have changed, Cassian. I know they have.” The droids speaks quietly.

“Everything has changed, Kay.” 

“You are still compromised.”

“I know.”

“Jyn Erso appears to be compromised too.”

Cassian smiles, and looks at the woman sleeping next to him, and thinks of the life he wants to lead with her by his side to make the sacrifice of those lost at Scarif worthwhile. “Yeah. I hope so.”

**Notes for the Chapter:**

> I feel like something much more angsty and full of survivor's guilt would have been much more in character for Cassian but I wanted to keep this light and focused on love <3


	3. Chapter 3

**Notes for the Chapter:**

> The third and final part of the fic I never meant to write! 
> 
> Also I decided that if Jyn, Cassian and K2 can survive then so can Admiral Raddus because I liked him.

Jyn doesn't think she has felt quite so alone and unsure of herself since the cave on Lahmu, or maybe the bunker where she waited for Saw. 

She's surrounded, on a ship full of people who can't really be called enemies. But everyone she has ever loved, or trusted, or called friend, is gone, except the one in front of her.

Cassian floats in the bacta tank, as silent and pale and still as he had been since that terrible moment on the shuttle when his coughing breaths had left his lips slick with blood and his belly had gone rigid, and his eyes had rolled back into his head and shut her out.

There are private quarters awaiting her, medical staff have told her repeatedly. Even Admiral Raddus himself has tried to coax her into comfort - only the best for the hero of Scarif - but she doesn't want to be alone. It's hard enough to just close her eyes as it is and not feel a dozen ghosts at her back or hear Chirrut's whispering chant, so she stays by Cassian's side.

His life was being held together by surgical stitches and implants, and the droids wouldn't tell her the odds of him waking again if the bacta was successful. _He may have been gone too long, lost too much time,_ they said. After so many years alone, it felt comforting and foolish, terrifying and wonderful to not want to lose someone again. If Cassian died, she would be alone in this new home he had welcomed her into and it didn't seem fair that he could leave her now after everything.

Or maybe it's just her fate, to lose everyone. She has often wondered if the name Erso was a curse.

Jyn shifts in the chair that seems designed to amplify her own aches and pains, her wrenched knee and hip in particular making it near impossible to sit comfortably in any position for long. The lights above have been lowered into a soothing blue glow for the last hour marking the beginning of the ship's sleep cycle. It makes Cassian look ghostly and pale in contrast, the terrifyingly fresh surgical wounds not yet soothed by bacta stark against skin that should be tanned and full of life. His brow his drawn, the brown eyes that had felt like home were shut, and the mouth that had been the first in so long to call her name, her real name, was hidden by the breathing apparatus.

There is a gurney in the corner of the room she could lie down on, and it's growing more tempting by the minute. _Just a little longer_ , she tells herself even as her eyes grow heavy and her chin drops towards her chest, _in case anything changes._

Her head snaps up as the door opens and her hand goes for a blaster that isn't there (she is welcome here, they keep telling her, that doesn't mean she gets a weapon just yet). But it's only K-2SO, and he ducks to enter the room. His new body is black and shiny and near spotless, and he reminds her of some of the teenage boys she had known among the Partisans, trying to fit into a body that seemed to be changing and growing overnight, not quite sure how to stand anymore. 

"There's no change, Kay." she says in a rough voice. Her throat is raw from Scarif and from secret tears. 

"Of course there isn't. The medics said it would be at least 12 hours before there would be any noticeable improvement, and it has only been 9." 

Jyn rolls her eyes and leans forward, elbows on knees and head in her hands as she stretches her neck. "I forgot, you're the practical type."

"If I thought anything could be accomplished just by sitting here, then I would. But as far as I'm aware there is no evidence to support _being stared at_ as a valid treatment for massive internal bleeding or as an aid to recovery from surgery."

He looms over her and she flops backwards into the chair, looking up. "I'm not staring. I just... he shouldn't be alone when he wakes up. Not after everything he's done. He deserves better."

The droid is silent for a long moment and she turns her gaze back to Cassian, until K-2SO speaks quietly. "That's what Cassian said."

"What?"

"That's what he said about you. If there was a chance for you to get off Scarif safely, even if the mission failed, I was to take it, because, he said, _she deserves better than what she's had._ "

Her throat closes painfully and her cheeks flush hot. She can't breathe, and her hands claw at her thighs. She thinks of their heavy gazes and the tangible _want_ between them, a living breathing thing like a tether drawing them tighter and tighter into each other's orbit, and knows now that _he felt it too._

Her voice sounds very small to her own ears when she says, "He shouldn't have - I never would have asked for that."

"He never would have asked for it before." K-2SO slouches and straightens and slouches again, as if he can't quite find the right level of freedom within his new body. "Since your meeting he has become unpredictable and distracted. It's dangerous."

Jyn nods, ash in her mouth. "I'm dangerous, you mean. For him."

K-2SO doesn't answer, and she takes his silence for affirmation. He turns to look at Cassian, still floating silently, and she wonders if he can hear them, muffled through glass and bacta like a dream. She thinks that Cassian has been alone like her for a long time, with no one but a droid and the cause to care about. 

"What if I left?"

"What do you mean?"

"If I left, let his life go back to how it was before." She stands on shaky, aching legs that threaten to buckle on her, and still has to crane her neck to look up at K-2SO. "If you told me that it would increase the probability of him being safe, being happy, then... I would do it, for him." _Even it would break my heart to lose another home._

"And what would you gain from this?"

Jyn shrugs her shoulders, holds her arms wide, and feels her heart hammer in her chest and ics settle in her stomach. "Nothing , Kay, I wouldn't be doing it for me. I mean it, if me being here is going to make things worse for him." She looks down at her feet to hide the burning in her eyes. "Enough people have died for me these last few days, I don't want him to get hurt for me too."

The droid tilts his head and stares down at her for a long moment, and Jyn raises her eyes to meet his gaze.

"Cassian thinks I don't understand why he asked me to look out for you."

"And do you?"

"Affection. Physical attraction. Loneliness." He shrugs stiffly. "I can't analyse the probability of human behaviour without some understanding of how emotions and hormones and all those other pathetic weaknesses affect your actions. And statistically it was always possible that as a human male in good health he would someday fall victim to those weaknesses, no matter how reckless they may make him."

Jyn blushes at what he is suggesting, not that she hadn't entertained the notion, and chuckles at the droid's disapproving tone. She used to think they were weaknesses, too. He turns away from her again and is quiet when he speaks.

"You should stay. I do not believe that you leaving would increase Cassian's well-being."

 _Or my own,_ she thinks, and bites her lip to swallow back a sob or a laugh or both because she feels the depth of meaning in the droid's approval of her presence. Jyn has never taken loyalty for granted, and she thinks K-2SO doesn't either.  
"Alright, Kay." she smiles and raps her hand against his back as she lets her legs bend beneath her to sit in the chair, and when she thinks he can't see she wipes her eyes with her sleeves.

They watch, together, silently.

Hours later, when Cassian has been pulled from the tank and dried off and left to breathe unaided, and she curls up on the next bunk in their room and listens to his gentle breathing as she falls asleep. K-2SO is a welcome sentinal, watching over them both. 

She wakes to the sound of his voice, and Kay's, and sees him sitting up across from her. Cassian's face lights up, little creases forming around his eyes, a smile tugs at his lips. His skin is vibrant again, his eyes open and beautiful and her heart flutters.

"Hi," she says, voice dusty and full of sleep. 

"Hey," he replies in a voice just as raw as her own, "you stayed."

He reaches his hand out, and she meets him halfway with her own. Their fingers lace together, and she feels at home, her broken pieces feel like they may mend eventually and she hopes that his will too.

Kay sighs and slumps, and Jyn swears he mutters something about weaknesses as he walks out of the room.

**Author's Note:**

> Half Cassian/Kay bromance, half rebelcaptain.


End file.
